System Integration

There is evidence to suggest that the next generation of cancer screening tests may employ not just one, but a small panel of less than ten biomarkers that together add statistical power to the detection of specific cancers. While immunoassays such as ELISA are well established for antigen-based biomarker detection, the fidelity of the assay is governed by the disassociation constant, Kd, of the antibody-antigen complex. If the antigen concentration is significantly below Kd, then the binding kinetics are slow and readout precision of the antigen-antibody complex can be degraded by noise.

We are developing a general approach for improving the performance of ligand – receptor assays. The approach is based on a nanofluidic device that controllably concentrates a dilute sample and an ultra-sensitive suspended microchannel resonant mass sensor that detects specific biomarkers within the concentrate. Since the amplification (or gain) of the concentrator is adjustable, the dynamic range and detection limit of the immunoassay can be governed by the properties of the concentrator and not Kd. Since the integrated concentration/detection system is batch fabricated by conventional foundry-level processing techniques, the cost per device could potentially be suitable for routine use in a clinical setting.